Voltmeter gauge jumps to full and headlights go bright problem

[Howieau]

Hey

In my St162 celica, lately as Ive been driving the voltmeter gauge jumps up to full (18v on the gauge) for breif moments then back to normal. It does these changes between full and normal very quickly at times. It doesnt do it all the time, it just happens randomly, sometimes it goes to full for a few seconds. Each time is goes to full voltage the battery light and what appears to be a 'car logo with the rear lights lit up' light flash on. Also the headlights go brighter (from what I remember, it happens so quick) and the revs drop. Nothing seems to stop it, like turning headlights on or off, turning radio on or off, overdrive or anything.

Perhaps a shorted circuit?
Could there be a voltage regulator of some sort malfunctioning?
Alternator overcharging?

Any ideas much appreciated.

[Duk]

My AW11 did that a few times, I believed it to be oil leaking onto the alternator (causing some sort of short circuit/malfunction ) from the distributor seal. Does the 3S have the distributor above the alternator?

[Talasas]

Could indeed be a dying regulator, though I've never come across a dead one yet.

[merc-blue]

its a volt regulator problem, and it will cause damage if not fixed in the near future.
Is the 3S a internal reg or external? replace your reg should fix your problem

[Darola]

Hey there mate... ALternator is over charging... simple as that... need to fix it asap as can cause burning of wires and cooking the battery....

first thing.. see if you have a bosch or nippon denso alternator

Bosh type:
now with the alternator it could possibly be just the voltage reg, the back part on the alternator with the plug on it and 2 screws holding it in....

now this can be changed easily and cheaply, make sure when u change it u disconnect the battery as it will spike and blow the new reg as u put it in...


now also it could be more of a problem then just the voltage reg, so best thing is to change the whole alternator.... or get a rebuild

Nippon denso:
Needs to be rebuilt by a auto elec as brush's and reg are all built in

If you are in nsw.. on central coast.. or near newy and syd, or on north side of syd... i do mobile mechanical and auto elec work

hope this helps

Ed

[petergoudie]

Keep your lights on in the interim. You need something to absorb the voltage spike so it does not blow the computer or other parts.